1. Field of the Invention
The present invention relates to a bar feeder for automatically feeding a bar to a bar machining apparatus.
2. Description of the Background Art
As a conventional bar feeder, there has been known one type designed such that one of a plurality of pieces of bars placed on a stock rack is pushed upwardly by a lifting arm, and the lifted bar material is received by a bar transfer arm and transferred to a guide rail by swinging the bar transfer arm, as disclosed, for example, in the Japanese Utility Model 2505419. In this type of bar feeder, a bar material is received by the bar transfer arm and transferred to the guide rail. Thus, a shock against the guide rail is less than that in another type designed to perform a bar loading operation by dropping a bar material from the stock rack onto the guide rail. This makes it possible to reduce vibration and noise in the bar feeder.
However, in the above bar feeder, it is required to equip each of the lifting arm and the bar transfer arm with a moving mechanism respectively, which causes an increase in the number of components of the bar feeder, and an extra maintenance task. Moreover, during the process of transferring a bar material to the guide rail, it is necessary to swing the bar transfer arm to a position adjacent to the lifting arm, and then move the lifting arm upwardly, in order to reliably pass a bar material from the lifting arm to the bar transfer arm. Therefore, in the above type of bar feeder, it is essential to set a timing of the movement of the lifting arm relative to the bar transfer arm.